Popped Tart Britney Porks Out!

BRITNEY SPEARS piling on the pounds again – chowing down junk food galore as fiancé indulges her every craving!

Britney and Kevin Federline have undergone a complete role rever­sal – the once-buff pop princess is porking up while her chubby ex-hubby is slimming down!

A source tells The ENQUIRER that Britney, 32, has been struggling to keep her weight in check as she kicks off her two-year residency at the Las Vegas Planet Hollywood Resort & Casino, and her boyfriend, David Lucado isn’t helping!

“David is undermining her hard work by sneaking her bags of Flamin’ Hot Cheetos, pepperoni Hot Pockets and her favorite chocolate treats, including Skor bars, Snickers bars and Hershey’s Whop­pers,” revealed a source.

Britney’s father Jamie – who controls her personal and financial affairs – found out that David, 28, was enabling his daughter’s junk-food habit and threatened to have him cut out of her life if he didn’t stop.

But “Britney loves that David allows her to indulge,” the source continued. “Their favorite date-night activity is making homemade, cheese-loaded pizzas in her wood-fire outdoor oven.”

Britney and David have been dating for a year. The ENQUIRER recently revealed that the pop star accepted his marriage proposal and the two are in the process of plan­ning a wedding in Hawaii.

The singer also recently said how hard she’s been working out to prepare for her Las Vegas revue. But despite her claims of daily 90-minute yoga sessions and hour-long cardio workouts, a source says Britney now ap­pears to be packing 135 pounds on her 5-foot-5 frame. And her jelly belly was evident on opening night of her show in late December.

Meanwhile, Brit’s ex-hubby K-Fed – who’s battled weight is­sues for years – recently dropped 30 pounds using Fresh Diet, a program that delivers healthy meals to customers daily. His goal is to lose another 50, says a friend, and he’s being cheered on by wife, Victoria, the former vol­leyball pro he wed last August.

But Britney appears to be going the opposite way.

“She’s at her best physically, mentally and emotionally when she’s on a strict low-sugar, high-protein diet and hitting the gym five days a week,” the source said.

Unfortunately, not only does David ply her with junk food, he doesn’t even exercise, the source added. Although

“Britney constantly raves about what a great, down-to-earth guy David is,” the source said, friends also fear his bad habits aren’t good for her.